This invention relates generally to railroad freight cars known as covered hopper cars and more particularly to a method for reinforcing certain areas of the frame of the opening of said hopper cars and a reinforcing kit for said frame.
Covered hopper cars have been constructed and arranged with a roof protecting the contents thereof from weather elements. Access to the interior of the car from above is through a rectangular hatch having a slot-like opening in the roof, the hatch opening extending the length of the car. The hatch is formed by a cowled coaming upstanding from the roof and extending circumferentially or peripherally of the opening. Individual hatch covers are secured lying upon the top margins of the coaming cowl to close the hatch.
A problem has developed in these hopper cars. Cracks in the roof material have occurred radiating from the sharp, rectangular corners of the upstanding coaming at the ends of the hatch. It appears that the cracks are caused by the concentration of stress at the corners of the hatch. The cracks allow water, etc. to leak through the roof to damage the contents of the car.
A prior solution has been the installation of a new roof sheet section providing an arcuate end to the hatch opening. This has removed the portion of the roof sheet having the cracks therethrough and has reduced the recurrence of the cracks by spreading stress across the arc at the end of the hatch opening. One shortcoming of this solution, however, is that the new roof sheet section fails to mate well with the curved junction or seam at the car roof and end wall. This leaves an opening not easily filled with the welding techniques that are desired to be used.
Another shortcoming of this solution concerns the reinforcement of the joints at the roof coaming. The roof coaming slopes inwardly of the hatch opening while a coaming web used with the new roof sheet is vertical or normal to the roof sheet. Thus the ends of the roof coaming, and the coaming web do not mate squarely but are angled relative to one another, leaving only a short, substantially vertical distance over which they can be joined by welding. The prior solution reinforced each joint with a single tongue of sheet metal that extended from the coaming web and that was secured, by such as rivets, to the end of the roof coaming. This tongue was twisted at the joint to conform to the different angularity of the coamings. The required twist dictates a thin reinforcing tongue while a thick reinforcing member is desired.
A desired replacement roof section should avoid these two shortcomings, be compatible with the inwardly slanting coamings of existing hopper car roofs, and provide suitable tolerance allowances for variations from car to car. Further a modification or "mod" kit should supply all the components necessary to repair the portion of the hopper car roof containing the cracks.